I got a response from the Hilton Corp - they pulled their ads!
.........
Thank you for your email. Embassy Suites is not a sponsor or advertiser of the David Letterman show. Several online ads appeared on a series of web sites, including cbs.com, among many others. These ads have since been taken down. The appearance of the ads on the CBS network web site does not suggest we condone or agree with Mr. Letterman’s views or comments.
We sincerely appreciate your email.
That’s huge.
You must make that announcement its own thread. It would be very encouraging to all of us.
Great news! Thanks for posting their response.